It would utilize satellites and polar orbits as indicated by these multiple satellites at altitudes of 500 to 800 miles. These satellites would sweep from north to south at uniform spacing and would essentially cover the earth, measuring the relatively detailed measurements I indicated on the last chart.

In addition, they would probably be complemented by satellites in what we refer to as a 24-hour orbit. By placing these satellites at 22,300 miles above the Equator, they will make one orbit per day and hence turn at the same rate as the earth and stay above some point on the ground. It should be then possible, with satellites of this type, to establish a scanning of large areas at the whim of the weather observer and watch interesting areas develop.

This system then would essentially take advantage of the unique capabilities of the satellite with relation to the meteorologist, and that is, its ability to give worldwide coverage all of the time, which he has never had in the past, and its ability to obtain types of measurements which we have never been able to obtain before.

PROJECT TIROS

There have been two, actually three attempts to launch meteorological satellites so far. Two failed during the launching and one was only successful to a minor degree in orbiting.

The next attempt will occur toward the end of this year with this satellite. The project is known as Project Tiros. It originated within the Department of Defense and upon creation of the NASA, or shortly thereafter, it was transferred to NASA by ARPA.

DESCRIPTION OF METEOROLOGICAL SATELLITE

This satellite is 270 pounds and about 42 inches in diameter, which spins about this vertical axis. It is covered with solar cells to power the equipment within it. This chart actually is slightly out of date. (The chart referred to appears on p. 77.)

Dr. CORTRIGHT. It has been modified, but it contains two television cameras, looking down the spin axis. It contains infrared detectors to perform this heat balance experiment which I referred to on an earlier chart.

Actually, it contains a battery of these infrared detectors to perform various heat balance experiments. It also contains magnetic tape storage and some of the usual electronic equipment to communicate with the satellite and to interrogate it for information.

The way this satellite will be used is this: It will be oriented so as to be looking at the interesting portion of the earth to us, namely, the North American Continent, and will be useful for a period, we hope, of about 90 days.

Beyond this, we have more ambitious satellites. It is obviously advantageous to get rid of the spin characteristics.

If we have a satellite which goes around the earth always looking down at the earth, then we can get truly worldwide coverage and this is the next satellite in the picture and one, incidentally (that is, the one which is earth-oriented), is the one which will be supported by the 1960 funds. This is in the amount of $10.8 million in the 1960 budget to cover the development of the more advanced satellite pay

load, and to cover ground operations and data analysis, meteorological analysis of the data we get with this particular payload which I just showed to you.

COMMUNICATION SATELLITES

Another area of equal importance at least, to all of us, is that of communication satellites.

It is fairly well acknowledged that the world is rapidly approaching a point where present forms of transatlantic communication can be saturated.

For example, a sevenfold increase in messages is expected by 1970, giving a total of 21 million transatlantic messages a year; and, at that rate, we would expect saturation of our cables by 1963. This is even

without television. Television, one channel alone, is equivalent to about 1,000 telephone channels. It does appear, after a considerable study, that the communications satellite is one of the most promising, if not the most promising, ways of facing up to this large communications problem.

NASA is conducting studies on two types of communications satellites. One is the passive communication satellite which is a large reflecting sphere 100 feet in diameter.

(The chart referred to appears on p. 79.)

Dr. CORTRIGHT. The technique of use here is to beam strong signals at the sphere and they are first reflected in this manner to cover a large area of the earth with a very weak signal.

By providing appropriate receiving equipment it is possible to pick up these weak signals at distances as much as 5,000 miles away from the satellite.

Now this particular satellite about which I have been talking will be launched by the end of this year or the first part of the next year and is shown in this next chart. This satellite, as I mentioned, was 100 feet in diameter, and will weigh not this [indicating] 65 pounds but closer to 165 pounds. It is made of Mylar plastic. There are many problems associated with it. There is the problem of keeping track of it in orbit and the problem of whether or not it will retain its spherical shape when the pressure inside is lost. It is inflated by trapped gases within the satellite from a package of 30 inches in diameter to the full 100 feet.

(The chart referred to appears on p. 80.)

Dr. CORTRIGHT. In addition, there is water packaged within this which will vaporize in orbit and will maintain its spheracity for some period of time.

Now this satellite is scheduled for a number of launchings in 1960-61, and, incidentally, it is necessary to proceed with a technique of rigidizing the structure, we feel, and we have allowed, in the budget of $4.7 million on this type of satellite, plus boosters, money for further developing this payload into a structure which will rigidize in orbit, and for packaging it into a multiple package so we can launch many with one shot.

I would like to point out here a single satellite will not do the job of this type. It will take as many as 25. If it is to be economical it will be required to launch perhaps a dozen of them at one shot, and we have some funds provided to develop this technique.

ACTIVE REPEATER COMMUNICATION SATELLITE

Now the last type of communication satellite I would like to mention is the active repeater. We have a small amount of funds in the budget to begin the development of this payload.

This satellite will be used in the 24-hour orbit, and three of them above the Equator could provide worldwide communication up to perhaps a latitude of 60° north or 60° south. The technique of utilizing this system [indicating], in order to go half way around the world would be to radio up to the satellite, back down to the ground, up to the next satellite and back down to the ground.

(The chart referred to appears on p. 81.)